The present invention relates to a new 9-aminoacridine derivative of the general formula (I) 
wherein A is hydrogen or 
(wherein X is oxygen or sulfur, R1, R2, R3, R4 and R5 are independently hydrogen, halogen, nitro, amino, hydroxy, C1-C4 lower alkylhydroxy, C1-C4 lower alkylamino, C1-C8 alkyl, C1-C4 lower alkoxy or C1-C4 lower alkoxycarbonyl and m and n are independently an integer of 0, 1 or 2),
R6, R7, R8 and R9 are independently C1-C8 alkyl or C1-C4 lower alkoxy,
and Y is hydrogen, amino, xe2x80x94Nxe2x95x90CHRxe2x80x2 (wherein Rxe2x80x2 is hydrogen, benzyl, C1-C8 alkyl or C1-C6 lower alkylamino), 
(wherein Rxe2x80x3 is hydrogen, benzyl, C1-C8 alkyl or C1-C6 lower alkylamino, and Rxe2x80x2xe2x80x3 is hydrogen, benzyl, C1-C8 alkyl or amino protecting group) or 
(wherein, X is as defined above, R1, R2, R3, R4, and R5 are independently hydrogen, halogen, nitro, amino, hydroxy, C1-C4 lower alkylhydroxy, C1-C4 lower alkylamino, C1-C8 alkyl, C1-C4 lower alkoxy or C1-C4 lower alkyloxycarbonyl, and m and n are independently an integer of 0, 1 or 2) or its pharmaceutically acceptable salt.
In the above compounds of the formula (I) wherein Y is 
(Rxe2x80x3 and Rxe2x80x2xe2x80x3 are as defined above.), there may be isomers of l-form, d-form or racemic form.
In the above definitions, C1-C8 alkyl means straight or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, isopentyl, hexyl, heptyl, octyl and 2-methylpentyl.
C1-C4 lower alkoxy means methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy or the like.
C1-C4 lower alkylcarboxy means an esterified carboxy by a lower alkyl.
C1-C4 lower alkylamino means methylamino, ethylamino, propylamino, butylamino or the like.
C1-C4 lower alkylhydroxy means methylhydroxy, ethylhydroxy, propylhydroxy or the like.
Amino protecting group may include benzyl, benzyloxycarbonyl, t-butoxycarbonyl, 2,2,2-trichloroethoxycarbonyl, methoxycarbonyl and 2-methylsulfonylethoxycarbonyl.
The inventors had studied for a long time to find new compounds having intensive antitumor activities. As a result, the inventors have found out that the compounds of the general formula (I), or acid addition salts thereof as defined above have not only prominent antitumor activities but also very low toxicities.
Accordingly, an object of the invention is to provide a compound of the general formula (I) or acid addition salt thereof having not only prominent antitumor activity but also very low toxicity.
Another object of the invention is to provide a process for the preparation of the compound of the general formula (I) or acid addition salt thereof.
The compounds of the present invention can be mixed with pharmaceutically acceptable vehicles by a conventional method to give pharmaceutical preparations to be used for prevention or treatment of various kinds of tumors.
Therefore, the other object of the present invention is to provide pharmaceutical preparations containing an effective amount of a compound of the general formula (I) or acid addition salt thereof as an active ingredient.
Acids which can be reacted with the compound of the general formula(I) to form acid addition salt thereof are pharmaceutically acceptable inorganic acids, organic acids, amino acids or sulfonic acids; for example, inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid and nitric acid; organic acids such as formic acid, acetic acid, propionic acid, succinic acid, citric acid, maleic acid and malonic acid; amino acids such as serine, cysteine, cystine, asparagine, glutamine, lysine, arginine, tyrosine and proline; sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid and toluenesulfonic acid.
Vehicles used in formulating pharmaceutical preparations containing the compound of the general formula (I) as an active ingredient are sweetening agents, binding agents, dissolving agents, aids for dissolution, wetting agents, emulsifying agents, isotonic agents, adsorbents, degrading. agents, antioxidents, preservatives, lubricating agents, fillers, perfume or the like; for example may include lactose, dextrose, sucrose, mannitol, sorbitol, cellulose, glycine, silica, talc, stearic acid, stearin, magnesium stearate, calcium stearate, magnesium aluminum silicate, starch, gelatine, tragacanth gum, glycine, silica, alginic acid, sodium alginate, methyl cellulose, sodium carboxy methyl cellulose, agar, water, ethanol, polyethylenglycol, polyvinyl pyrrolidone, sodium chloride, potassium chloride, orange essence, strawberry essence and vanilla aroma.
Daily dosage of the compound of the general formula (I) may be varied depending on age, sex and degree of disease, but preferably 1 mg to 5,000 mg per day may be administered by once to several times.
The compound of the general formula (I) according to the present invention may be prepared by following schemes I, II or III. 
wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R1xe2x80x2, R2xe2x80x2, R3xe2x80x2, R4xe2x80x2, R5xe2x80x2, A and Y are as defined above, Yxe2x80x2 is H or NH2, and Lie is a leaving group such as hydrogen and halogen atom.
According to the above scheme, a compound of the general formula (a) is reacted with a xe2x80x94C(xe2x95x90X)xe2x80x94 group-providing agent in organic solvent to give a compound of the general formula (b), and successively the compound (b) is reacted with a compound of the general formula (c) to give a compound of the general formula (I).
The xe2x80x94C(xe2x95x90X)xe2x80x94 group-providing agent used may include, for example, 1,1-carbonyldiimidazole, 1,1-carbonylthiodiimidazole, phosgene, thiophosgene, carbonyldiphenoxide and phenylchloroformate, and it may be used in an amount of 1-1.5 equivalent, preferably 1-1.1 equivalent to the starting compound.
The reaction may be carried out preferably in a conventional organic solvent such as tetrahydrofuran, dichloromethane, chloroform, acetonitrile and dimethylformamide.
In addition, the reaction may be carried out preferably in the presence of a coupling agent. Such coupling agent may include conventional inorganic or organic bases, for example, including sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, pyridine and DBU, and it may be used by 1-5 equivalents.
The reaction may be carried out at a temperature between 3xc2x0 C. and boiling point of a used solvent, preferably at 50xc2x0 C.-100xc2x0 C. for 5-48 hours, preferably for 10-24 hours. 
wherein, R6, R7, R8, R9, Rxe2x80x2, A and Y are as defined above.
According to the above scheme II, a compound of the general formula (d) above may be reacted with HCORxe2x80x2 in the presence of a base and a conventional organic solvent to give a compound of the general formula (I).
In the above reaction, the conventional organic solvent may include tetrahydrofuran, dichloromethane, chloroform, acetonitrile and dimethylformamide.
In addition, the reaction is carried out in the presence of a conventional inorganic or organic base as a coupling agent, and such a conventional base may include sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, pyridine and DBU, and maybe used in an amount of 1-5 equivalents.
The reaction may be carried out at a temperature between 3xc2x0 C. and boiling point of the solvent used, preferably at 50xc2x0 C.-100xc2x0 C. for 5-48 hours, preferably for 10-24 hours. 
wherein, R6, R7, R8, R9, Rxe2x80x3, Rxe2x80x2xe2x80x3, A and Y are as defined above.
According to the above scheme III, a compound of the general formula (d) may be reacted with a compound of following formula, 
in the presence of a base and a conventional
organic solvent to give a compound of the general formula (I).
The resulting compound of the formula (I) according to the scheme III may have isomers of l-form, d-form or racemic form.
In the above reaction, the conventional organic solvent may include tetrahydrofuran, dichloromethane, chloroform, acetonitrile and dimethylformamide.
And also the reaction is carried out preferably in the presence of a conventional organic or inorganic base as a coupling agent, and such a base may include sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, pyridine and DBU, and it may be used in an amount of 1-5 equivalents.
The reaction may be carried out at a temperature between 3xc2x0 C. and boiling point of the solvent used, preferably at 50xc2x0 C.-100xc2x0 C. for 5-48 hours, preferably for 10-24 hours.
In the above processes according to the present invention, in case any acid material is formed, a suitable basic material may be added before reaction in order to eliminate the acid material from the reaction system. Such a basic material may be alkali metal hydroxide, alkali earth metal hydroxide, alkali metal oxide, alkali earth metal oxide, alkali metal carbonate, alkali earth metal carbonate, alkali metal hydrogen carbonate, alkali earth metal hydrogen carbonate such as sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, magnesium oxide, calcium oxide, potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, magnesium bicarbonate, sodium bicarbonate and calcium bicarbonate, or organic amines.
The compound of the general formula (c) is a known compound, described in, for example, J. Med. Chem., 1995, 38, 3226 or may be prepared in a similar method thereto.